Case gauge

[bobcat93]

Ive never used one of these tools.
Im sure you guys know all about them.
How do these work?

I would think this is a reloading tool that needs to be made at the same time, your rifle barrel is chambered, with the same reamer.
By the gunsmith.
Correct? At least ive been offered that service in the past when i ordered a barrel. But never really felt the need for it.

I am trying to wrap my head around how this product can be on a shelf and not numbered to a mating barrel.

Or maybe the numbers are so small it doesnt matter. Between the chambers, and gauge

What is your guys perspective on this tool, and do you use one when setting up your dies
Thank you

 

[K22]

I would not recommend using them to set up your full-length sizing die (F/L). Instead, I would use a bump gauge and caliper to set up the F/L die.

The reason is that most case gauges are sized to SAMMI specs. For example, the difference between the upper and lower step of my Wilson Case Gauge is .005". The process for using this gauge is to size the case so ideally fits between the upper and lower step which is approximately .0025". This can result in an unnecessary amount of sizing.

Using a bump gauge and caliper gives you a precise measurement of the fired case and sized case comparison thus enabling you to make precise adjustments to the F/L die to yield optimum sizing for your specific rifle.

With that said, they can be used for a quick qualitative check for chamber fit for rifles manufactured to SAMMI specs.

Before the advent of bump gauges, case gauges were the first attempt to bring attention to optimum sizing. I used them for years before converting to the more precise method of bump gauges.

Before that, the old, but effective method was to use the rifle chamber in a trial-and-error process to size the case and check in the rifle chamber until optimum fit was achieved. It is still a good idea to spot check your F/L size adjustment with a few cases in the rifle chamber to verify proper chamber fit.

 

[243winxb]

Useless tool. Most measure head to datum. Some also measure diameter.

The head of the tool has to lengths. Minimum & Maximum. If case head is between the 2, head to datum is ok. This does not guarantee the round will chamber.
The rifle chamber is the best tool.



The best may be cut with the roughing reamer. The finish reamer may be larger in diameter.

 

[Hoser]

For setting headspace on a die, not very good.

If the gauge was cut with the same reamer as you chamber and you are just checking to see if they will fit in your chamber, they are ok.

But I use fired brass and my chamber for the above.

 

[Oso]

They are are useful tool for spot checking pistol ammo and bulk rifle ammo. The generic off-the-shelf case gage is SAAMI tolerances usually featuring two height elevations (min & max) at the base of the case and then also at the case mouth. The depth indications milled into the base of the gage measure the shoulder location (base of case to the shoulder). The depth indications milled into the top of the gage (case mouth) measure the overall length of the case. There are other versions of the case gage that also include a cut-away to show/test bullet seating depth in relation to chambers throat/bore. Again, these are generic representations. It helps visualize, but each rifles chamber is unique/different.

If you are loading pistol ammo or bulk ammo that can be used in different rifle, such as AR15’s, then the Case Gage helps test whether the case or cartridge (loaded ammo) fits within the general guidelines for dimensions. It also help quickly identify any issues you might have… out of spec ammo as result of excessive expansion of case base or excess flare of case mouth. During reloading of pistol I routines drop a cartridge into case gage to spot check. I drop all of my bulk AR ammo through case gage just as a spot check, especially if I am using range brass.

For precision reloading you are correct that it is only useful if the gage exactly matches your chamber, which is only happens if it is cut by reamer cutting your chamber. This is a custom tool… not the generic version you buy off the shelf.

 

[chromatica]

A good way to zero in on proper case length is to use a combination of Go/NoGo gauges together with the RCBS Precision Mic. The bolt should close over the Go Gauge and stop short of closing over the NoGo gauge. Insert each of these gauges into the Precision Mic to show you where the min and max case lengths are. Then refine the measurement by placing your actual fired brass into the Precision Mic and screwing down the barrel till it stops.

 

[RegionRat]

I am trying to wrap my head around how this product can be on a shelf and not numbered to a mating barrel.

Not all folks are trying to run in the same games.

Think about the guys who are loading buckets full of 223 or pistol ammo and burn it all in one weekend in action matches.

Those ammo checker style gages are designed to ensure that ammo fits a standard MIN chamber. This way, they will have a little less chance of a failure to feed due to an ammo size issue.

Precision rifle sizing shares some of the same issues, but we are really talking about a different world.

 

[std7mag]

Best case gauge you can get for your pistols.

Your barrel!

Pull the barrel out and plunk your cartridge in it.
Then you KNOW that it works in your pistol!

 

[209jones]

Never really understood why folks buy a case gauge, chamber has tolerances, dies have tolerances. Why add in a third set of tolerances to contend with?

 

[Ilmo]

Whidden makes a case gauge for a lot of calibers …..
w

 

[NF1E]

I have been using Sheridan gauges as a reference and like the process. Whatta Hobby!